Zombietron 1 - Cemetery Guy Updated Demo

The flow of the game is simple. You fight waves of enemy until you die. Every 3 waves, you must fight against a Boss. As you kill Monsters and obtain Unholy Tomes, you gain experience points needed to go up levels. At each new level, you are rewarded by a various amount of Promotion Points. Those points can be used to raise your five characteristics, your weapons or to obtain armour. But as you gain levels, so do your enemies